Methods for improving uplink (UL) coverage, throughput and transmission latency are being investigated in the Third Generation Partnership Project (3GPP). In order to achieve these goals, scheduling and assigning of UL physical resources will be moved from the RNC to the Node-B.
The Node-B can make decisions and manage UL radio resources on a short-term basis better than the RNC. However, the RNC still retains coarse overall control of the cell with EU services so that the RNC can perform functions such as call admission control and congestion control.
A new medium access control (MAC) entity called MAC-e is created in a WTRU and the Node-B to handle the transmission and reception of enhanced dedicated channel (E-DCH) transmissions. There may be several independent uplink transmissions processed between the WTRU and UMTS terrestrial radio access network (UTRAN) within a common time interval. One example of this is MAC layer H-ARQ or MAC layer ARQ operation where each individual transmission may require a different number of transmissions to be successfully received by the UTRAN. Proper assignment of data blocks to ARQ/H-ARQ processes for transmission is necessary for operation of the EU services. This function includes rules for retransmitting failed transmissions, prioritization between different logical channels and provisioning of quality of service (QoS) related parameters.